Manganese-base brazing alloys



United States Patent 3,316,086 MANGANESE-BASE BRAZING ALLOYS Arthur T. Cape, Monterey, Calif, assignor to Coast Metals, Inc., Little Ferry, N.J., a corporation of Delaware No Drawing. Filed June 16, 1964, Ser. No. 375,659 3 Claims. (Cl. 75-134) This invention relates, as indicated, to manganese-base brazing alloys, but has reference more particularly to alloys of the type disclosed in my US. Patent No. 3,124,451.

In my US. Patent No. 3,124,451, there is disclosed an alloy consisting of about 63 to 69% manganese, and nickel and cobalt in amounts of about 14 to 18% of each.

In the Cremer et al. Patent No. 2,856,281, there is described a brazing alloy containing up to 60% manganese, and 35 to 89% nickel, in the absence of cobalt, but wherein cobalt may be present as an optional ingredient for replacing up to about 90% by weight of the nickel. It is further stated in that patent that additions of silicon and boron to the alloy have the effect of lowering the melting point, and silicon, in amounts of about 1 to 8%, and boron, in amounts of about 0.3 to 3%, are accordingly included in the alloy. The alloy is thus essentially a manganese-nickel alloy, containing substantial amounts of silicon and boron, but in which cobalt may be used as an optional ingredient.

While the alloy of my aforesaid patent is highly advantageous, due to its lack of susceptibility to age hardening, I have found that alloys, containing less than 63%, that is, from about 50 to about 60% manganese, but containing from about 18 to about 24% each of nickel and cobalt, with the cobalt in an amount approximately equal to the amount of nickel and preferably in an amount greater than the amount of nickel, while more susceptible to age hardening than the alloys of my aforesaid patent, may be used satisfactorily in applications in which shelf life of the alloy is not of importance, and for applications in which the brazed part, for example, amissile or rocket, is used for only a short time at its temperature of firing.

Moreover, I have found that while the addition of silicon to the alloys of the aforesaid Cremer et al. patent has the efiect of lowering the melting point of the alloy, the addition of like amounts of silicon to the alloy of the present invention has the effect of increasing the melting point of the alloy substantially.

It is therefore desirable to restrict the silicon content in the alloy of the present invention to an amount less than 0.5%.

Boron may be present in the alloy, as an optional ingredient, in amounts up to about 2% to aid the flow characteristics of the alloy, While not materially affecting any of the other characteristics of the alloy.

The alloy of the present invention accordingly falls within the following ranges, it being understood that in all cases, the cobalt is present in the alloy in an amount approximately equal to the amount of nickel and preferably in an amount greater than the amount of nickel.

Percent Manganese 50-60 Nickel 18-24 Cobalt 18-24 Boron 0-2 Silicon Less than 0.5

The alloy may contain minor amounts of impurities, such as iron, carbon, chromium, etc., which are incidental to the process of manufacturing the alloy, it being understood, however, that the aggregate amount of such impurities does not exceed about 2%.

A preferred alloy, within the foregoing range, is one consisting of about 58% manganese, about 20% nickel, about 21% cobalt, and about 1% boron.

While the Cremer et al. patent contemplates an alloy containing less than 60% manganese, as Well as nickel and cobalt, the alloy of the present invention is distinguished from that of Cremer et al., in that both nickel and cobalt are mandatory constituents of the alloy, and the cobalt must be present in an amount not less than and preferably greater than the amount of nickel.

It will be understood that slight changes may be made in the alloy, without departing from the spirit of the invention, or the scope of the appended claims.

Having thus described my invention, I claim:

1. A brazing alloy consisting of about 50 to about 60% manganese, about 18 to about 24% nickel, and about 18 to about 24% cobalt, the cobalt being present in an amount not less than and preferably greater than the amount of nickel.

2. A brazing alloy, as defined in claim 1, containing boron in an amount up to about 2%, and containing silicon in an amount less than 0.5%.

3. A brazing alloy, consisting of about 58% manganese, about 20% nickel, about 21% cobalt, and about 1% boron.

References Cited by the Examiner UNITED STATES PATENTS 10/1958 Cremer et al -134 3/1964 Cape 75134 

1. A BRAZING ALLOY CONSISTING OF ABOUT 50 TO ABOUT 60% MANGANESE, ABOUT 18 TO ABOUT 24% NICKEL, AND ABOUT 18 TO ABOUT 24% COBALT, THE COBALT BEING PRESENT IN AN AMOUNT NOT LESS THAN AND PREFERABLY GREATER THAN THE AMOUNT OF NICKEL. 